Conventional medicine has long held that as humans grow, so our brain changes, and that once we stop growing, our brains also stop changing. Anecdotally, most people say that the brain stops changing at around 18 years of age, and that the adult brain stays the same throughout adulthood, until disease, trauma, or atrophy occurs.
Enter the brilliant researchers at Dartmouth, who have recently challenged the myth of the unchanging brain. They studied groups of students from ages 18 to 35, and determined that significant changes continue to occur as the brain ages.
The implications for this research is vast and leveling. What is the neuroscientific difference between an adult and an adolescent? Are there milestones in development that predispose us to certain behaviors at one point in our lives and not in others? Could some people have such a slowly-developing brain that they are more like children in adult bodies?
I suspect that as we learn more about the brain and aging, clearly defined social boundaries will begin to erode, and categories like adulthood and adolescence will be seen on a blurry continuum, and not so clearly delineated as the case may be today.